CODEWITHSUNDEEP
javascriptphpajaxjson
user2036852
user2036852

Reputation:

JSON.parse throws unexpected token error

JSON.parse throws an "unexpected token" error when I try to parse multiple JSON objects. I have used this approach before, but only when the array involved one row of query results.

Any help would be greatly appreciated. Thank you

The Error 

Uncaught SyntaxError: Unexpected token {

The JavaScript

if(window.XMLHttpRequest){
    var request = new XMLHttpRequest();
    } else {
    var request = new ActiveXObject(microsoft.XMLHTTP);
    }
    request.open('POST', 'controllers/engineersOutput.php', true);
    request.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
        request.onreadystatechange = function(){
        if((request.readyState==4) && (request.status==200 || request.status==304)) {

        var str = request.responseText;
        var data = JSON.parse(str);

        console.log(data);

        }
    }
    request.send();

The PHP

public function getEngineerDetails(){
        include "connect.php";
        $query = "SELECT * FROM `engineers`";
        $result = mysqli_query($con, $query);
        while($row=mysqli_fetch_assoc($result)){

            $name = $row['name'];
            $pic =  $row['pic'];
            $insertedEngs = array( "name"=>$name, "pic"=>$pic );
            echo json_encode($insertedEngs);
        }

    }

Upvotes: 2

Views: 804

Answers (2)

Kevin
Kevin

Reputation: 41885

Most likely your JSON string created from server is malformed because of the way you created it.

Don't construct the JSON string while inside the loop, construct and complete the array first, then finally encode:

public function getEngineerDetails() {

    include "connect.php";
    $query = "SELECT * FROM `engineers`";
    $result = mysqli_query($con, $query);

    // define a container first
    $data = array();

    while($row = mysqli_fetch_assoc($result)){
        // while inside the loop
        // construct the array first
        $insertedEngs = array("name" => $row['name'], "pic" => $row['pic']);

        $data[] = $insertedEngs; // continually push 
    }

    // then encode output when done
    echo json_encode($data);

}

Upvotes: 0

Pointy
Pointy

Reputation: 413702

It looks like your code is returning a sequence of JSON-encoded objects, and that's not going to be recognizable to a JSON parser. Collect your objects into an array (in the PHP code) and then echo the whole array via json_encode when it's complete. Then your client will receive a JSON array.

Upvotes: 1

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